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METRO RED LINE'S METHANE REVIEW & CONCRETE TESTS PROVE SAFETY

 METRO RED LINE'S METHANE REVIEW & CONCRETE TESTS PROVE SAFETY
 LOS ANGELES, July 31 /PRNewswire/ -- The methane control systems used in the Metro Red Line subway will be fully effective in preventing methane from posing a risk to public safety. These are the findings of an investigation conducted by Fluor, Daniel Inc., and independent consulting firm with extensive construction and mining experience, presented to the Rail Construction Corp. (RCC), builders of the Metro Rail system.
 Also presented today were the results of quality assurance tests initiated by the construction management firm that show the Red Line's building materials and their installation exceed their own design criteria, as well as national standards.
 The RCC has spent $1.8 million to conduct tests on the subway's construction materials. "The extent of the tests of the building materials and the review of methane procedures emphasize the RCC's willingness to go to great lengths to examine concerns regarding the quality and safety of the Red Line," said Ed McSpedon, RCC president/chief executive officer.
 Three methods of inhibiting, detecting and eliminating methane are used to provide a high level of safety; the use of High Density Polyethylene (HDPE), a thick plastic liner that envelopes the tunnels; a hypersensitive sensor detection system; and a high capacity ventilation system.
 Methane, an odorless, clear gas that is prevalent in the Los Angeles basin, is not explosive until it reaches levels of 50,000 to 150,000 parts per million. Very sensitive devices -- both hand-held and stationary -- in place along the Metro Red Line are set at 15 ppm (warning) and 20 ppm (alarm). Methane gases are ever present in the air in Los Angeles. Therefore, there will always be an insignificant measurement of it in the tunnels as well.
 Concrete, the main ingredient for the subway's tunnels and stations, underwent a series of tests measuring its strength and thickness. About 290,117 cubic yards of concrete were poured to build Segment 1 beneath downtown Los Angeles -- enough to build a 1,000-foot-high concrete tower with a base the size of a baseball diamond.
 A total of 7,772 cylinder samples of the concrete mixture of sand, cement and gravel were taken during its pouring and were processed through the Smith Emery laboratory of Los Angeles. (The facility is a general construction materials testing lab that examines soil, steel, concrete and other building supplies in accordance with standards set by the American Society for Testing and Materials (ASTM).)
 Cylinder sample findings show the average test result to be at 5,600 pounds-per-square-inch (PSI) -- 1,600 PSI over the design requirements set at 4,000 PSI by the ASTM.
 "Concrete is the basic building material for a subway because of its high level of compression strength," said McSpedon. "A tunnel must be able to withstand pressure from its entire circumference, as well as the forces and loads experienced during an earthquake.
 "All evaluation testing and investigation support the integrity of our construction and confirm that its safety is beyond reproach," said McSpedon.
 CONCRETE TESTING PROCEDURES
 -- During cylinder sample testing, the concrete pieces are
 compressed until they crush, allowing lab workers to measure
 pounds of force applied per square inch to calculate strength;
 -- Thickness is verified by onsite inspectors who monitor the
 concrete forms prior to the pouring of the mixture;
 -- A secondary measuring tool is "ground penetration radar."
 Examination of the tunnel is made through the use of radar
 beam equipment; and
 -- Another step of testing thickness involves removal of two- to
 three-inch diameter "cores" from the tunnels themselves to
 ensure that the tunnels meet the 12-inch design requirements.
 This ongoing method employs random sampling to avoid cutting
 holes throughout the subway.
 There is yet an additional level of reinforcement on the Red Line in that it is actually a "double tunnel" -- built with layers of concrete, a thick plastic liner, steel ribs and wooden lagging in some areas, -- all sandwiched by an inner layer of concrete.
 Thickness tests show that all 40,000 feet of the twin tunnels, with the exception of a small contained area near Union Station meet the 12-inch standard. The original contractor is studying the best remedy to reinforce this area.
 The small patch of thinner tunnel was uncovered in a quality assurance audit that was ordered by the RCC after a former inspector made statements that there were deficiencies in the tunnel structure. Of the 16 issues presented, all others were either found to be invalid or already corrected in the standard inspections procedures in the building of the Metro Rail system.
 "We'll take input regardless of the credibility of the source because safety is paramount to our construction project. We are now more aware than ever of the excellence of our program," McSpedon said.
 EARTHQUAKE SAFETY
 The Red Line was put to the test during the recent 7.4 earthquake originating in the Yucca Valley desert region, as well as the 1987 5.9 Whittier earthquake. No structural damage, cracks or incidents of gas or water leakage were found after a series of inspections. Subway tunnels are considered to be one of the safer places to be during an earthquake. A tunnel flexes with the ground as opposed to older buildings that crack instead of sway. The very elliptical shape of the tunnel absorbs any ground movement.
 OPERATIONS
 Prior to the Metro Red Line Segment 1 opening in March 1993, it is undergoing a series of operations testing, including:
 -- 10,652 electrical tests and 894 mechanical tests on equipment
 which operates the stations and tunnel systems;
 -- 320,000 individual tests on train control, fire and emergency
 systems, radio, communication, closed circuit television and
 other high tech systems prior to opening;
 -- 93 integrated tests including train operation; and
 -- 13 emergency drills for emergency response teams.
 -0- 7/31/92
 /CONTACT: Roberta Tinajero or Stephanie Brady of LACTC, 213-244-6565, ext. 6792/ CO: Los Angeles County Transportation Commission ST: California IN: SU:


EH-KJ -- LA020 -- 5835 07/31/92 18:26 EDT
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Date:Jul 31, 1992
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